1. Technical Field
The invention concerns a device for applying a coating material to an optical fiber with a nozzle holder, a coating nozzle arranged inside the nozzle holder, a coating chamber located before the coating nozzle in the direction of travel of the fiber, and at least one inlet channel for a coating material, which is connected to the coating chamber.
2. Description of the Prior Art
Such a device for applying a coating material is used to manufacture an optical glass fiber for telecommunications, which is drawn from a glass preform. Guiding the glass fiber over pulleys requires providing the glass fiber with a coating in order to protect it against damage from unacceptably high mechanical stresses. To that end, the optical glass fiber is coated with one or several layers, for example of a polymer material, where these have regular mechanical differences when several layers are applied. As a rule, the outer layer of the coating on the optical fiber is also used to identify the optical fiber in order to be able to identify individual fibers from a multitude of fibers.
It is therefore customary to use twelve or more differently colored coating materials in devices for applying coating material to optical fibers. Since the known coating devices only have one feed line for the coating material to be applied to the optical fibers, a change of color requires changing the storage container with the supply line to the device, as well as a complete cleaning of the coating device. To avoid correspondingly long idle and change-over times of the coating device, it is possible to arrange two or more identical devices for applying differently colored coating materials in a line, where each of these devices is used to apply just one color. However, such an arrangement occupies a large space in the production line. Furthermore, the additional devices for applying coating material find very little use. If the production line is changed over to coating materials of other colors, it is associated with a sizable effort.